1. Field of the Invention
This invention relates to a method of assembling a plurality of parts, for example, in assembly of a vehicle body, and a system for carrying out the method.
2. Description of the Prior Art
In an assembly line for example one, for assembling by welding a plurality of panels into a unit such as a side portion of a vehicle body, there have been sometimes used robots. However, in the past, the robots have been disposed along a single conveyor line to carry out operations in place of workmen. In other words, in the past, robots have been used only for carrying out work that would otherwise be performed by workmen and the capability of the robot has not been fully used, though the number of workmen required for a given manufacturing step can be reduced. That is, robots have contributed to neither simplification of the manufacturing lines nor better use of the space in the plant.
As a method of assembling or integrating a plurality of parts such as various panels into a unit like a vehicle body, there has been known the so-called convergence assembly procedure in which main parts are separately assembled in different assembly lines and the assembled parts are converged to one station and assembled into a unit.
For example, a plurality of assembly lines A, B and C for assembling different parts are provided in parallel to each other as shown in FIG. 1. An integration station D is provided at the terminus C' of the assembly line C, and a conveyor line E for converging parts is provided to extend from the terminus A' of the assembly line A to the integration station D via the terminus B' of the assembly line B. This arrangement is disadvantageous in that the conveyor line E for conveying parts is necessary in addition to the assembly lines A, B and C, thereby complicating the arrangement, and that the layout of the assembly lines A, B and C is limited since, for instance, the termini A', B' and C' of the assembly lines A, B and C must be aligned with each other in order to connect them by way of the conveyor line E.